The Deep Penetration Incrediblob Structure Stability Studies

Deep penetration projectile will get reaction force from the target when it penetrates into concrete vertically, which, will lead to such phenomenon as axial compression in projectile body, stress concentration in cross section and lack of internal charge stability. In order to interpret this phenomenon and obtain a better structure.Based on the theory of elastic-plastic mechanics, stress wave propagation, Taylor impact, and cavity expansion, this paper analyses axial compression and the force in the cross section in projectile body. We use finite element analysis software AUTODYN-2D to simulate the processes where different projectile bodies penetrate into semi-infinite concrete target. We get the time curve of analyses axial compression, force in the cross section and internal charge pressure when cylindrical structure, reinforcing rib structure (including cylindrical reinforcing rib and arc stiffener reinforcing rib), and variable cross-section structure are in the process of penetration respectively. The results are almost in accordance with the theoretical calculation.what is more; we make comparative analysis on the three structures. It shows that in process of deep penetration, axial compression and force in the cross section of the reinforcing rib structure are relative to its placed position; compared with other structures, variable cross-section structure has both minimal axial compression and minimal changing value of force in cross section, it exists an optimal value. Maximum pressure in variable cross-section structure will be smaller than that in cylindrical structures on condition that its internal charge is installed with buffer. Therefore, the variable cross-section structure can effectively guarantee stability of the structure and improve the internal charge stability in the process of penetration.